This invention pertains to mobile cranes of the type having booms which may be extended hundreds of feet into the air and which also include ground-engaging wheels which render the crane mobile. Cranes of this type employ radially extending outriggers for stabilizing the crane when in the operative position. An example of such a crane is shown in the U.S. patent applications Ser. Nos. 203,941; 203,942; 203,943 and 203,944 all filed Nov. 7, 1980. In cranes of that type, as well as other prior art cranes, the outrigger assemblies are swingable along side the wheels of the crane when the latter is to be transported; and this creates a wide crane, particularly when of the extremely large size.
The present invention provides a wheeled crane of the type having a boom carried by a revolvable upper that is mounted on an elongated main frame. The elongated main frame has a series of ground-engaging wheels along its length and on either side of the main frame. More specifically, the present invention provides radially swingable outriggers for such a crane and which can be not only swung from a radially extending stabilizing position to a transport position along the main frame; but the invention furthermore contemplates means for rotating the rectangular in cross-section outrigger assemblies about their longitudinal axes so that the outriggers can be rotated from a stabilizing position in which their major transverse axis is in a vertical direction to a transport position in which the major transverse axis of the outrigger is in a horizontal position and the outrigger can be stored above the wheels and compactly along the side of the main frame. The invention furthermore contemplates power means for not only rotating the outrigger assembly about its longitudinal axis approximately 90.degree., but also provides for positively shifting the outrigger against the main frame for being locked therewith, and away from the main frame to facilitate rotation of said outrigger about its axis through the 90.degree. travel. Power means are also provided for positively locking the outrigger assemblies to the main frame in the stabilizing position.